JP2018182912A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high performance electric rotating machine by enhancing the position accuracy of a brush holder.SOLUTION: An electric rotating machine includes a motor case having a tubular yoke portion and provided with a magnet in the yoke portion, a front case 3 provided so as to close an opening of the motor case and having a first contact convex portion 30c1, an armature rotatably supported by the motor case and the front case 3 and having a commutator, a plurality of brushes 72 that are in slidable contact with the commutator, and a brush holder 71 that holds a plurality of brushes 72 so as to protrude and retract toward the commutator and has a second positioning convex portion 84, and the brush holder 71 is fastened and fixed to the front case 3 by one bolt and the second positioning convex portion 84 is disposed so as to be in contact with the first contact convex portion 30c1 toward the tightening direction of the bolt.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a rotating electrical machine.

  As a rotating electrical machine, for example, there is an electric motor with a brush. In this type of electric motor, a plurality of magnets are disposed on the inner peripheral surface of a cylindrical yoke. Also, an armature is disposed inside the magnet in the yoke. The armature is mounted on an end bracket (front bracket, rear bracket) that covers both ends of the yoke, a rotating shaft rotatably supported, an armature core fixed on the rotating shaft and coil wound around, and a rotating shaft And a commutator fixed to the armature core so as to be adjacent to the armature core and to which the end of the coil is connected.

Further, the end bracket is provided with a plurality of brushes in sliding contact with the commutator, a brush holder for holding the brushes, and a terminal for electrically connecting the external power supply and the brushes. The plurality of brushes are held by the insulating brush holder. The brush holder is often fastened and fixed to the end bracket by a bolt.
Then, when the power of the external power supply is supplied to the coil through the terminal, the brush, and the commutator, a predetermined magnetic field is generated in the armature core. A magnetic attraction and repulsion force is generated between the magnetic field and the yoke magnet to rotate the armature.

Japanese Patent Application Laid-Open No. 2004-260892

  By the way, when fastening and fixing a brush holder to an end bracket with a volt | bolt, when a bolt is tightened, there existed a case where this volt | bolt and a brush holder corotate. Therefore, there is a possibility that it is difficult to position the brush holder on the end bracket with high accuracy. If the position accuracy of the brush holder is lowered, the position of the brush will vary and the motor performance will be lowered.

  Then, this invention is made in view of the situation mentioned above, Comprising: The high-performance rotary electric machine is provided by raising the position accuracy of a brush holder.

  In order to solve the above-mentioned problems, the rotary electric machine according to the present invention has a cylindrical yoke portion, and a motor case provided with a magnet in the yoke portion and an opening portion of the motor case are closed. An end case having a first positioning protrusion, an armature rotatably supported by the motor case and the end case, and having a commutator, a plurality of brushes slidably in contact with the commutator, and the plurality of brushes. And a brush holder having a second positioning protrusion and holding the brush in a retractable manner toward the commutator, the brush holder being fastened and fixed to the end case by a single bolt, It is particularly preferable that the positioning convex portion is disposed to abut on the first positioning convex portion in the tightening direction of the bolt. To.

  With this configuration, when the bolt is tightened so as to fasten and fix the brush holder to the end case by the bolt, the second positioning convex portion of the brush holder corotating with the bolt is the first positioning convex of the end case Abuts the part. Thereby, positioning of the brush holder with respect to an end case is performed with high precision. For this reason, the position of the brush with respect to the end case is stabilized, and the performance of the rotating electrical machine can be stably improved.

  In the rotary electric machine according to the present invention, the end case has a third convex portion, while the brush holder has a fourth convex portion, and the fourth convex portion loosens the bolt. It is characterized in that it is disposed to abut on the third convex portion in the direction.

  With this configuration, when the bolt is loosened, the fourth convex portion of the brush holder corotating with the bolt abuts on the third convex portion of the end case. For this reason, when loosening a volt | bolt, it can prevent that a brush holder rotates together with this volt | bolt. Therefore, when assembling the brush holder, rattling at the time of removal can be suppressed as much as possible.

  In the rotary electric machine according to the present invention, the first positioning convex portion has a function of the third convex portion.

  By configuring in this way, it is possible to reduce the material cost for suppressing the rattling at the time of removal when assembling the brush holder. In addition, the end case and the brush holder can be miniaturized.

  In the rotary electric machine according to the present invention, the first positioning convex portion is a rib provided on the end case, and the contact surface of the rib with the second positioning convex portion passes through the rotation axis of the armature. The contact surface of the second positioning convex portion with the first positioning convex portion is formed to face the straight line in the radial direction and the axial direction, and the contact surface of the second positioning convex portion with the first positioning convex portion extends along the axial direction and holds the brush It is characterized in that it is formed to face a straight line passing through the center of the direction.

  With this configuration, the circumferential center of the brush can be made along the radial straight line passing through the rotation axis in a state where the second positioning convex portion is in contact with the first positioning convex portion. Thereby, the end face of the brush can be brought into contact with the outer peripheral surface of the commutator with high accuracy, and the life extension of the brush can also be achieved.

  According to the present invention, when the bolt is tightened so as to fasten and fix the brush holder to the end case by the bolt, the second positioning convex portion of the brush holder corotating with the bolt is the first positioning convex portion of the end case. Abut. Thereby, positioning of the brush holder with respect to an end case is performed with high precision. For this reason, the position of the brush with respect to the end case is stabilized, and the performance of the rotating electrical machine can be stably improved.

It is a perspective view of a starter motor in an embodiment of the present invention. It is a sectional view of a starter motor in an embodiment of the present invention. It is the perspective view which saw the front case in embodiment of this invention from the motor case side. It is a disassembled perspective view of the components provided in the front case in the embodiment of the present invention. It is the top view which looked at the front case in embodiment of this invention from the motor case side, Comprising: The state which removed the brush holder unit is shown. It is sectional drawing in alignment with the AA of FIG. It is sectional drawing in alignment with the BB line of FIG. It is the perspective view which saw the brush holder unit in embodiment of this invention from the bottom part side of front case. It is a perspective view which shows the positional relationship of the motor case and brush holder unit in embodiment of this invention. It is the side view which saw the 1st holder main body in the embodiment of the present invention from the diameter direction inner side. It is an explanatory view showing behavior of a head of a terminal bolt at the time of tightening a nut in an embodiment of the present invention. It is the top view which looked at the attachment state of the brush holder unit to the front case in embodiment of this invention from the motor case side.

  Next, an embodiment of the present invention will be described based on the drawings.

(Starter motor)
FIG. 1 is a perspective view of the starter motor 1 and FIG. 2 is a cross-sectional view of the starter motor 1.
As shown to FIG. 1, FIG. 2, the starter motor 1 is used as a starter motor for two wheels, for example. The starter motor 1 includes a substantially bottomed cylindrical motor case 2, a substantially bottomed cylindrical front case 3 closing the opening 2 a of the motor case 2, and a space closed by the motor case 2 and the front case 3. The main components are an armature 4 rotatably housed in the housing, a terminal 64 and a brush holder unit 70 provided on the front case 3 for supplying power to the armature 4, and a bracket 5 attached to the motor case 2. . In the following description, the rotational axis L1 direction of the armature 4 is simply referred to as the axial direction, the rotational direction of the armature 4 is referred to as the circumferential direction, and the radial direction of the armature 4 orthogonal to the axial direction and the circumferential direction is referred to simply as the radial direction. .

(Motor case)
The motor case 2 is formed, for example, by deep drawing an iron plate. That is, the motor case 2 is constituted by the substantially cylindrical yoke portion 6 and the bottom portion 7 integrally formed at the end of the yoke portion 6 opposite to the front case 3. At the peripheral edge of the opening 2 a of the motor case 2, an inlay portion 2 c whose outer diameter is reduced in diameter by a step is formed. The front case 3 is inlay fitted to the inlay portion 2c. Further, a notch 2b (see FIG. 9) for determining the relative position between the motor case 2 and the brush holder unit 70 is formed in the inlay portion 2c. The details of the notch 2b will be described later.

A plurality of magnets 8 are provided on the inner peripheral surface of the yoke portion 6 at equal intervals in the circumferential direction, and the magnetic poles are arranged in order in the circumferential direction. Here, in the present embodiment, the number of magnets 8 is set to four (see FIG. 12). That is, the starter motor 1 is a four-pole motor.
Further, a bearing portion 9 for rotatably supporting the rotary shaft 14 of the armature 4 at the center in the radial direction is formed in the bottom portion 7 so as to protrude toward the side opposite to the front case 3. The bearing portion 9 is formed in a substantially bottomed cylindrical shape so that the bottom portion 10 faces axially outward by deep drawing processing. A slide bearing 12 is press-fitted to the inner peripheral surface of the circumferential wall 11 of the bearing portion 9. One end of the rotary shaft 14 is rotatably supported by the slide bearing 12.

  A bearing-side boss 13 is formed on the bottom 10 of the bearing 9 at a radial center, that is, on the same straight line as the rotation axis L1 so as to project axially inward (toward the front case 3). The bearing side boss 13 is formed by pressing the motor case 2 (bearing portion 9). That is, the outer surface side (axially outer side) of the bottom portion 10 is recessed on the bearing side boss 13.

(bracket)
The bracket 5 is attached to the bottom 7 of the motor case 2. The bracket 5 is formed by pressing a metal plate of iron or the like and forming an L-shaped cross section. More specifically, the bracket 5 has a motor-side bracket portion 34 that abuts on the bottom portion 7 of the motor case 2.
The motor side bracket portion 34 is formed to pass along the rotation axis L1 and to be long in the radial direction. In the following description, the extending direction of the motor side bracket portion 34 is referred to as the longitudinal direction of the motor side bracket portion 34.

  Further, the motor side bracket portion 34 is formed in a substantially hat shape long along the radial direction. That is, the motor-side bracket portion 34 is disposed at a substantially central position in the longitudinal direction, and the projecting portion 36 bent so as to avoid the bearing portion 9 of the motor case 2 and bent and extended from both ends in the longitudinal direction of the projecting portion 36 It is comprised by two flange parts 37 contact | abutted to the bottom part 7 of motor case 2. As shown in FIG. The bolt 100 is inserted through the flange portion 37 and the bottom portion 7 of the motor case 2 where the flange portion 37 abuts. The bolt 100 is screwed into the front case 3. Thus, the motor case 2 and the bracket 5 are fastened together to the front case 3.

The bulging portion 36 of the motor side bracket portion 34 is constituted by a pair of rising portions 41 rising from the flange portion 37 and a flat upper wall portion 42 extending so as to straddle the tips of the rising portions 41. The upper wall portion 42 is in contact with the bottom portion 10 of the bearing portion 9 formed on the motor case 2.
A bracket-side boss 43 is formed on the upper wall portion 42 so as to protrude toward the bearing portion 9 at a position corresponding to the bearing-side boss 13 formed in the bearing portion 9. The bracket side boss 43 is formed by pressing the bracket 5 (motor side bracket portion 34).

  Here, the shape of the bracket side boss 43 is the same as the shape of the bearing side boss 13 formed in the bearing portion 9. Therefore, in a state in which the upper wall portion 42 of the motor side bracket portion 34 is in contact with the bearing portion 9, the bracket side boss 43 is fitted in the recess of the bearing side boss 13. Thereby, positioning of the bracket 5 with respect to the motor case 2 is performed.

The bracket-receiving portion 35 is formed on one side of the motor-side bracket portion 34 formed in this manner in the surface direction of the motor-side bracket portion 34 (the surface direction of the flange portion 37 and the surface direction of the upper wall portion 42). It is bent and extended along the direction perpendicular to the Further, the bracketed portion 35 extends from the motor side bracket portion 34 toward the opposite side to the motor case 2.
The bracketed portion 35 is attached to, for example, an engine case or a vehicle body (not shown), and is for fixing the starter motor 1 to the engine case or the vehicle body. The bracketed portion 35 is flat and extends in a substantially square shape in plan view. At corner portions of the bracket-receiving portion 35 opposite to the motor-side bracket portion 34, bolt insertion holes (not shown) for fastening and fixing the bracket-receiving portion 35 to the engine case or the vehicle body are formed.

(Armature)
The armature 4 mainly includes a rotary shaft 14 rotatably supported at one end on the slide bearing 12, and an armature core 15 and a commutator 16 externally fitted and fixed to the rotary shaft 14. The other end of the rotary shaft 14 protrudes from the front case 3 via a connection portion 24 described later of the front case 3. A pinion gear 17 (see FIG. 1), which is connected to a ring gear of an engine (not shown) via a one-way clutch or the like, is externally fitted and fixed to the other end of the protruding rotary shaft 14. In addition, center concave portions 98 are formed on both end surfaces of the rotary shaft 14 coaxially with the rotary axis L1, respectively. The center recess 98 is formed in a substantially circular shape as viewed in the axial direction.

  Here, the center recess 98 has two functions. As the first role, the center recess 98 has a role of fitting the chuck claws of a tool (not shown) and holding the rotation shaft 14 when cutting the rotation shaft 14. In addition, as a second role, it has a role of avoiding interference with the bearing side boss 13 formed in the bearing portion 9 of the motor case 2.

  The armature core 15 is disposed at a position corresponding to the magnet 8 of the rotation shaft 14. The armature core 15 is formed by laminating electromagnetic steel sheets, and has a plurality of teeth 18 radially extending about the rotation axis 14. An axially long dovetail slot (not shown) is formed between the teeth 18, and a coil 19 is wound around the teeth 18 through the slots.

  The commutator 16 is disposed at a position corresponding to the front case 3 of the rotation shaft 14. The commutator 16 is for supplying a current to the coil 19. The commutator 16 is composed of a substantially cylindrical commutator main body 20 having insulation and fixed to the rotation shaft 14 and a plurality of conductive segments 21 provided on the outer peripheral surface of the commutator main body 20. . The segments 21 are arranged side by side at predetermined intervals in the circumferential direction. The terminal part of the coil 19 is connected to such a segment 21.

(Front case)
FIG. 3 is a perspective view of the front case 3 as viewed from the motor case 2 side. FIG. 4 is an exploded perspective view of FIG. 3, that is, an exploded perspective view of parts provided in the front case 3.
As shown in FIGS. 2 to 4, the front case 3 is formed, for example, by aluminum die casting. At the periphery of the opening 3 c of the front case 3, an inlay portion 3 d whose inner diameter is enlarged by a step is formed. The front case 3 is attached to the motor case 2 by the inlay fitting of the inlay portion 3 d with the opening 2 a of the motor case 2.

  A substantially bottomed cylindrical bearing 22 is formed on the bottom 3a of the front case 3 so as to project toward the side opposite to the motor case 2 at most of the central portion in the radial direction. The bottom 22 a of the bearing 22 faces axially outward. A rolling bearing 23 is fitted and fixed to the inner circumferential surface 22 b of the bearing portion 22. The other end side of the rotating shaft 14 is rotatably supported by the rolling bearing 23.

  Further, a substantially cylindrical connecting portion 24 is formed on the bottom 22 a of the bearing 22 at the center in the radial direction so as to protrude toward the side opposite to the motor case 2. The connecting portion 24 is a portion where the starter motor 1 (front case 3) is connected to an engine case (not shown). The inner surface side of the connecting portion 24 is in communication with the bearing portion 22. Thereby, the other end of the rotating shaft 14 protrudes outward in the axial direction via the connecting portion 24.

A seal ring 25 is provided on the inner peripheral surface side of the connecting portion between the connecting portion 24 and the bearing portion 22. The seal ring 25 is for ensuring the sealing performance between the front case 3 and the rotating shaft 14.
Further, an O-ring groove 26 is formed on the outer peripheral surface of the connecting portion 24 substantially at the center in the axial direction. An O-ring 27 is attached to the O-ring groove 26. The O-ring 27 is for ensuring sealing between the engine case (not shown) and the front case 3.

FIG. 5 is a plan view of the front case 3 as seen from the motor case 2 side, and shows a state in which the brush holder unit 70 is removed.
As shown in FIG. 4 and FIG. 5, in the bottom portion 3 a of the front case 3, a recess 28 is formed on the entire outer peripheral portion on the inner surface side. The recess 28 is formed such that the thickness t1 between the recess 28 and the inner circumferential surface 22b of the bearing 22 is constant. The terminal 64 and the brush holder unit 70 are disposed in the recess 28 thus formed.

  Further, in the peripheral wall 3b of the front case 3, two bolt seats 29 are integrally formed on the inner peripheral surface side and on the recess 28. The two bolt seats 29 are disposed to face each other about the rotation axis L1. In each bolt seat 29, a female screw portion 29a in which the bolt 100 is screwed is engraved.

  Furthermore, a plurality of ribs 30 for improving the strength of the front case 3 are formed in the recess 28 of the front case 3 so as to extend between the bearing portion 22 and the peripheral wall 3 b. Specifically, the plurality of ribs 30 have a total of four side ribs 30 a disposed on both sides of one bolt seat 29 across the bolt seat 29 and disposed in parallel to one another. In addition, it has one center rib 30b which is disposed on a straight line L3 passing through the rotation axis L1 orthogonal to the center of the two female screw parts 29a and the straight line L2 passing through the rotation axis L1. Furthermore, the first contact convex portion 30c1 and the second contact convex portion 30c2 disposed between the center rib 30b and the side rib 30a, and the first contact convex portion 30c1 and the second contact convex portion 30c2 And an intermediate rib 30d disposed point-symmetrically about the rotational axis L1.

  In addition, the first contact convex portion 30c1, the second contact convex portion 30c2, and the intermediate rib 30d are arranged along the radial direction. Furthermore, the first contact side surface 30e on the side rib 30a side of the first contact convex portion 30c1 and the second contact convex portion 30c2 faces the radial straight line L4 passing through the rotation axis L1 and the axial direction.

  Further, a bolt seat 31 having a substantially circular shape as viewed in the axial direction is formed at one of the four side ribs 30 a at a connection portion with the bearing portion 22. The bolt seat 31 is for grounding one of the two brushes 72 that constitute the brush holder unit 70. At most of the radial center of the bolt seat 31, an inlay convex portion 32 is formed to protrude. The inlay convex portion 32 temporarily positions the front case 3 and the brush holder unit 70. A female screw 33 is engraved at the radial center of the inlay convex portion 32. The details of the method of grounding the brush 72 and the method of temporarily positioning the brush holder unit 70 with respect to the front case 3 will be described later.

  Furthermore, a terminal seat 50 having a flat side surface 50a is integrally formed on the inner peripheral surface of the peripheral wall 3b of the front case 3. The terminal seat 50 is disposed to face the center rib 30 b about the rotation axis L 1, and is integrally formed on the peripheral wall 3 b of the front case 3. The terminal seat 50 is for attaching the terminal 64 to the front case 3.

  The terminal seat 50 is formed over the entire axial direction of the peripheral wall 3b of the front case 3, and is formed in a substantially rectangular shape as viewed from the inner side in the radial direction so that the circumferential length is slightly longer than the axial length. ing. A terminal insertion hole 51 is formed in the central portion of the terminal seat 50 in the axial direction and circumferential direction so as to penetrate the peripheral wall 3 b. The terminal bolt 52 constituting the terminal 64 is inserted into the terminal insertion hole 51 from the side surface 50 a side of the terminal seat 50.

  The terminal bolt 52 is formed of a conductive metal member. For example, the terminal bolt 52 is formed of SCM 45 or the like. The terminal bolt 52 is inserted into the terminal insertion hole 51, and a head 53 is integrally formed at an end of the shaft 53 on the terminal seat 50 side, the shaft 53 projecting radially outward from the peripheral wall 3b of the front case 3 And 54. An O-ring 47 is attached to the terminal insertion hole 51 in the peripheral wall 3 b of the front case 3, and insulation between the terminal insertion hole 51 and the shaft 53 of the terminal bolt 52 is secured.

In addition, a nut 59 is screwed on the tip side of the shaft 53 opposite to the head 54. The nut 59 is used to fasten and fix a terminal (not shown) extending from an external power supply to the terminal bolt 52. The ring insulator 49 and the washer 48 are attached to the terminal bolt 52.
The ring insulator 49 and the washer 48 are disposed between the nut 59 and the peripheral wall 3 b of the front case 3. The washer 48 cooperates with the nut 59 to fasten and fix a terminal (not shown) extending from the external power source to the terminal bolt 52. The ring insulator 49 is made of resin and secures insulation between the nut 59 and the front case 3.

  On the other hand, the head portion 54 of the terminal bolt 52 is formed by a plate-like metal member so as to be approximately one turn smaller than the side surface 50a of the terminal seat 50 and substantially square with one side along the axial direction There is. The head 54 of the terminal bolt 52 thus formed is held by the terminal insulator 55 provided on the side surface 50 a of the terminal seat 50 via the intermediate member 60.

6 is a cross-sectional view taken along the line A-A of FIG. 3, and FIG. 7 is a cross-sectional view taken along the line B-B of FIG.
As shown in FIG. 4, FIG. 6, and FIG. 7, the terminal insulator 55 is formed in a box shape having an opening 55a on one surface, for example, by a resin such as phenol resin. That is, the terminal insulator 55 is formed in a substantially square shape whose one side extends in the axial direction so as to correspond to the side surface 50 a of the terminal seat 50. The terminal insulator 55 is formed by integrally molding a flat bottom wall 56 in contact with the side surface 50 a and a frame portion 57 erected along the outer peripheral edge of the bottom wall 56. The terminal insulator 55 is disposed in the recess 28 of the front case 3, and the frame portion 57 is in contact with the recess 28.

The head 54 of the terminal bolt 52 is housed inside the frame portion 57. That is, the frame portion 57 is formed in a substantially square shape whose one side extends in the axial direction so as to surround the outer peripheral portion of the head portion 54 of the terminal bolt 52. One side 57 a of the frame portion 57 in contact with the recess 28 (bottom 3 a) of the front case 3 is in contact with the bottom 3 a of the front case 3. An insertion hole 58 through which the shaft 53 of the terminal bolt 52 can be inserted is formed at the center in the axial and circumferential directions of the bottom wall 56. The hole diameter of the insertion hole 58 is set to be slightly larger than that of the shaft 53.
In the following description, one side 57a of the frame portion 57 on the bottom 3a side of the front case 3 is a bottom side 57a, the side opposite the bottom side 57a in the axial direction is an upper side 57b, and a circumferential direction connecting the bottom 57a and the upper side 57b. The sides on both sides are called side 57c.

  The intermediate member 60 is formed by pressing a plate material having conductivity that is harder than the terminal insulator 55 and softer than the terminal bolt 52. For example, the intermediate member 60 is formed by pressing a brass plate material. The intermediate member 60 is formed in a substantially U-shaped cross section so as to be accommodated in the terminal insulator 55. That is, the intermediate member 60 is disposed to abut on the bottom wall 56 of the terminal insulator 55, and the base portion 61 has one side formed in a substantially square shape along the axial direction so as to correspond to the shape of the bottom wall 56. And two side wall portions 62a and 62b (upper side wall portion 62a, lower side wall portion 62b) bent and extended along the inner side surface of the frame portion 57 from both ends (axial direction both ends) of the base portion 61. It is done.

  In the base portion 61, at a position corresponding to the insertion hole 58 of the terminal insulator 55, an insertion hole 61a communicated with the insertion hole 58 and through which the shaft portion 53 of the terminal bolt 52 can be inserted is formed. Thus, the terminal bolt 52 is inserted from above the base portion 61 of the intermediate member 60, and the shaft portion 53 of the terminal bolt 52 is protruded from the outside in the radial direction of the peripheral wall 3b of the front case 3 via the terminal insulator 55. Can.

The distance between the two side wall portions 62a and 62b is set to be substantially equal to or slightly longer than the length of one side of the head 54 of the terminal bolt 52. Therefore, in a state where the head 54 of the terminal bolt 52 and the intermediate member 60 are accommodated in the terminal insulator 55, the head 54 and the base portion 61 of the intermediate member 60 are in contact with each other. The two side wall portions 62a and 62b of the member 60 abut.
Furthermore, of the two side wall portions 62a and 62b, a pigtail connection is made to the upper side wall portion 62a located on the opposite side (the opening 3c side of the front case 3) of the front case 3 with the base portion 61 interposed therebetween. The portion 63 is bent and extended along the axial direction. A pigtail 77 of a brush 72 described later is connected to the pigtail connection portion 63.

Here, the size of the head portion 54 of the terminal bolt 52, the size of the base portion 61 of the intermediate member 60, and the size of the side walls 62a and 62b are formed to satisfy the following conditions. That is,
(A) Of the two side wall portions 62a and 62b, the lower side wall portion 62b on the bottom side 57a side of the frame portion 57 is in contact with the bottom side 57a of the frame portion 57.
(B) A minute clearance C1 is formed between the upper side wall portion 62a and the upper side 57b of the frame portion 57.
(C) A micro clearance C2 is formed between circumferentially opposite ends of the head portion 54 of the terminal bolt 52 and the corresponding sides 57c of the frame portion 57, and the periphery of the base portion 61 of the intermediate member 60 is formed. A minute clearance C3 is formed between the direction both ends and the side 57c of the corresponding frame portion 57.
In the following description, the condition (A) is referred to as condition (A), the condition (B) is referred to as condition (B), and the condition (C) is referred to as condition (C). It is called.

  Further, the front case 3 straddles the two side ribs 30a on the side where the bolt seat 31 is formed, and the first contact convex portion 30c1 and the middle rib 30d adjacent to the side ribs 30a in the circumferential direction. , And a brush holder unit 70 is disposed.

FIG. 8 is a perspective view of the brush holder unit 70 as viewed from the bottom 3 a of the front case 3.
As shown in FIGS. 3, 4 and 8, the brush holder unit 70 is disposed at a position radially opposed to the commutator 16 of the armature 4 in a state where the starter motor 1 is assembled. The brush holder unit 70 mainly includes a resin brush holder 71 and two brushes 72 accommodated in the brush holder 71. The brush holder 71 includes two holder bodies 81 and 82 (a first holder body 81 and a second holder body 82), and a connecting portion 74 for connecting the two holder bodies 81 and 82 across the two holder bodies 81 and 82. And are integrally molded.

The two holder bodies 81 and 82 are arranged at intervals of 90 ° in the circumferential direction. More specifically, the first holder main body 81 of the two holder main bodies 81 and 82 is disposed on the first contact convex portion 30c1. Further, of the two holder main bodies 81 and 82, the second holder main body 82 is disposed on the intermediate rib 30d.
Each holder main body 81, 82 is formed in a rectangular parallelepiped shape so as to be slightly longer along the radial direction when viewed from the axial direction. Each of the holder main bodies 81 and 82 is formed in a box shape having first openings 81a and 82a on the bottom 3a side of the front case 3 and second openings 81b and 82b on the radially inner side. .

  The brushes 72 are accommodated in such holder main bodies 81 and 82, respectively. Further, the tips of the brushes 72 can be retracted radially inward (toward the commutator 16) via the second openings 81b and 82b of the holder main bodies 81 and 82, respectively. Furthermore, in each of the holder main bodies 81 and 82, a spring 78 is accommodated at the base end side of the brush 72 in a compressed state. Thus, the brush 72 is always urged radially inward (toward the commutator 16), and the tip end of the brush 72 is in sliding contact with the segment 21 of the commutator 16.

  Further, a slit 76 is formed at the center in the circumferential direction on the upper wall 75 opposite to the first openings 81 a and 82 a of the holder main bodies 81 and 82. The slits 76 are formed to communicate with the second openings 81 b and 82 b, respectively. The slit 76 is used to pull the pigtail 77 made of copper wire connected to the brush 72 to the outside of the holder body 73.

  The terminal of the pigtail 77 pulled out of the first holder body 81 is grounded (details will be described later). On the other hand, the end portion of the pigtail 77 drawn out of the second holder body 82 is connected to a pigtail connection portion 63 provided on the intermediate member 60 of the terminal 64, for example, by brazing. Since the pigtail connection portion 63 is formed of brass, it is substantially equivalent to the specific heat of the pigtail 77, and the pigtail 77 can be easily soldered to the pigtail connection portion 63 by brazing.

Here, in the first holder main body 81, a positioning protrusion 83 is formed in a protruding manner at the radially outer end of the upper wall 75. Further, in the first holder main body 81, a positioning convex portion 84 and a position restricting convex portion 85 which are protruded in a bifurcated shape are formed at an edge portion of a radial outer end of the first opening 81a.
The positioning protrusion 83 is for determining the relative position of the brush holder 71 and the motor case 2. The positioning projection 83 is formed in a plate shape. The positioning projection 83 includes a rising portion 83a which rises in the axial direction from the upper wall 75, and a tongue portion 83b which is bent and extended radially outward from the tip of the rising portion 83a. The rising portion 83 a is disposed flush with the radially outer end wall 81 c of the first holder body 81. The positioning protrusion 83, that is, the circumferential center L6 of each of the rising portion 83a and the tongue piece 83b is a straight line L5 extending in the axial direction and passing through the circumferential center of the first holder main body 81 (second opening 81b). It is located on top (see FIG. 10).

FIG. 9 is a perspective view showing the positional relationship between the motor case 2 and the brush holder unit 70. As shown in FIG.
As shown in the figure, when the starter motor 1 is assembled, the tongue piece 83 b of the positioning projection 83 of the brush holder 71 is located at the periphery of the opening 2 a of the motor case 2. The notch 2 b formed on the periphery of the opening 2 a of the motor case 2 is disposed at a position corresponding to the tongue piece 83 b of the brush holder 71.

  The notch 2b is formed in a substantially rectangular shape so as to correspond to the shape of the tongue 83b. The circumferential width of the notch 2 b is set to be substantially the same as or slightly larger than the circumferential width of the tongue 83 b of the positioning projection 83. Thus, the tongue piece 83b is fitted into the notch 2b, and the relative position between the motor case 2 and the brush holder 71 (brush holder unit 70) is accurately determined.

FIG. 10 is a side view of the first holder main body 81 of the brush holder 71 as viewed from the radially inner side (commutator 16).
As shown in FIGS. 8 and 10, the positioning convex portion 84 and the position restricting convex portion 85 which are formed to project from the brush holder 71 are respectively flush with the radial end wall 81c of the first holder main body 81. It has been extended. Further, the positioning convex portion 84 is formed in a substantially triangular shape in plan view in the radial direction so as to be tapered toward the tip. Further, the positioning convex portion 84 is formed such that one side 84a is along the axial direction and faces a straight line L5 passing through the circumferential center of the brush 72 (first holder main body 81, second opening 81b) .

On the other hand, the position restricting convex portion 85 is formed in a substantially rectangular shape in a radial plan view. The position restricting convex portion 85 is extended so that one side 85 a is flush with the side wall 81 d opposite to the second holder main body 82 of the first holder main body 81.
Here, the distance K1 between the positioning convex portion 84 and the position restricting convex portion 85 is set to be slightly larger than the thickness t2 of the first contact convex portion 30c1 (see also FIG. 5). There is. Then, the first contact convex portion 30 c 1 is interposed between the positioning convex portion 84 and the position regulating convex portion 85. That is, the position restricting convex portion 85 is located on the opposite side to the positioning convex portion 84 across the first contact convex portion 30c1.

As shown in FIGS. 3, 4 and 8, a connecting portion 74 connecting the two holder main bodies 81 and 82 extends in an arc shape along the outer peripheral surface of the bearing portion 22 (commutator 16). In other words, the connecting portion 74 extends in a substantially arc shape so as to correspond to the shape of the peripheral wall 3 b of the front case 3.
Further, the connecting portion 74 is formed such that the cross-sectional shape along the axial direction is L-shaped. That is, the connecting portion 74 is a base portion 86 straddling between end portions of the two holder main bodies 81 and 82 on the front case 3 side, and an inner circumferential wall portion 87 straddling between radial inner ends of the two holder main bodies 81 and 82. And consists of.

  A pedestal 88 is formed in the base portion 86 near the second holder main body 82. In other words, the pedestal 88 is formed at a position corresponding to the inlay convex portion 32 of the front case 3 in the base portion 86. The base 88 is formed with a through hole 88 a which can be fitted to the inlay convex portion 32. The bolt 101 is screwed into the female screw portion 33 of the inlay convex portion 32 from the top of the pedestal 88 externally fitted to the inlay convex portion 32. Thereby, the brush holder 71 is fastened and fixed to the front case 3. The details of the method for fastening and fixing the brush holder 71 to the front case 3 will be described later.

Here, a terminal 89 is attached to the end portion of the pigtail 77 drawn out of the first holder main body 81. When the brush holder 71 is fastened and fixed to the front case 3 by the bolt 101, the brush holder 71 and the terminal 89 are tightened together.
Further, in a state in which the pedestal 88 is externally fitted to the inlay convex portion 32, the tip end surface of the pedestal 88 and one surface of the base portion 86 become substantially flush. For this reason, when the brush holder 71 is fastened and fixed to the front case 3, the terminal 89 contacts the inlay convex portion 32 of the front case 3. Thus, the end of the pigtail 77 pulled out of the first holder body 81 is grounded (body earth).

In addition, the brush holder unit 70 has a base portion 90 disposed on the bottom portion 3 a side of the front case 3 in the brush holder 71.
The base portion 90 closes the first opening 81 a of the first holder main body 81 and the first opening 82 a of the second holder main body 82. That is, the base portion 90 is configured by two base portion main bodies 91 closing the respective opening portions 81a and 82a, and a connecting portion 92 which straddles the two base portion main bodies 91 and connects the two base portion main bodies 91. It is done.

The base portion main body 91 is formed in a substantially rectangular shape as viewed from the axial direction so as to correspond to the openings 81 a and 82 a of the holder main bodies 81 and 82. On each side of the side walls 81d and 82d of the holder main bodies 81 and 82, claws 91a are formed in the base main body 91 so as to protrude. The base portion 90 is snap fit fixed to the brush holder 71 by the claw portion 91a.
In the connecting portion 92, an opening 92a for exposing the through hole 88a is formed at a position corresponding to the through hole 88a of the pedestal 88 formed in the brush holder 71. As a result, even if the base portion 90 is attached to the brush holder 71, the base projection 32 of the front case 3 can be fitted to the pedestal 88.

(Assembly of terminal and brush holder unit to front case)
Next, assembly of the terminal 64 and the brush holder unit 70 to the front case 3 will be described.
First, assembling of the terminal 64 to the front case 3 will be described.
When assembling the terminal 64 to the front case 3, the intermediate member 60 and the terminal insulator 55 are inserted through the terminal bolt 52 into the shaft 53 in advance. At this time, the intermediate member 60 and the head 54 of the terminal 64 are accommodated in the frame portion 57 of the terminal insulator 55.

Thereafter, the shaft portion 53 of the terminal bolt 52 is inserted from the terminal seat 50 side of the front case 3. At this time, the pigtail connection portion 63 of the intermediate member 60 is directed to the opening 3 c side of the front case 3. Then, the bottom wall 56 of the terminal insulator 55 is brought into contact with the side surface 50 a of the terminal seat 50.
The terminal insulator 55 and the intermediate member 60 may be disposed on the side surface 50 a of the terminal seat 50 of the front case 3 without inserting the intermediate member 60 and the terminal insulator 55 into the shaft portion 53 of the terminal bolt 52 in advance. In this case, the shaft 53 of the terminal bolt 52 is then inserted through the terminal insulator 55, the intermediate member 60, and the front case 3.

  Subsequently, the O-ring 47, the ring insulator 49, the washer 48, and the nut 59 are inserted in this order into the shaft portion 53 of the terminal bolt 52 projecting radially outward from the peripheral wall 3b of the front case 3, and tightened by the nut 59. To go.

FIG. 11 is an explanatory view showing the behavior of the head 54 of the terminal bolt 52 when the nut 59 is tightened, and corresponds to the view on arrow C in FIG.
As shown in the figure, when the nut 59 is tightened, the terminal bolt 52 tries to rotate together with the nut 59 (see arrow Y1 in FIG. 11).

  Here, in a state where the head 54 of the terminal bolt 52 and the intermediate member 60 are housed in the terminal insulator 55, the head 54 and the base portion 61 of the intermediate member 60 are in contact with each other. Furthermore, the two side walls 62a and 62b of the intermediate member 60 are in contact with the two opposite sides of the head 54 in the direction of the rotation axis L1. Further, the head portion 54 of the terminal bolt 52 housed in the terminal insulator 55 satisfies the conditions (A), the conditions (B) and the conditions (C). That is, in the frame portion 57, the lower side wall portion 62b in contact with one side of the head 54 is in contact with only the bottom side 57a.

Therefore, when the head portion 54 tries to rotate, the base portion 57a of the frame portion 57 is pressed by the head portion 54 through the lower side wall portion 62b of the intermediate member 60 (see arrow Y2 in FIG. 11). Try to deform. At this time, the pressing force is positively applied to the bottom side 57a of the frame portion 57, but the pressing force of the head portion 54 is hardly applied to the other side (the upper side 57b and the side 57c) of the frame portion 57.
The bottom side 57 a of the frame portion 57 is in contact with the recess 28 (bottom 3 a) of the front case 3. Therefore, the front case 3 receives the pressing force of the head 54 and the deformation of the bottom side 57 a is suppressed by the front case 3. As a result, the rotation of the head portion 54 is prevented, and the nut 59 can be firmly tightened to the shaft portion 53 of the terminal bolt 52.

  The intermediate member 60 is harder than the terminal insulator 55 and softer than the terminal bolt 52, and is made of, for example, a brass plate. For this reason, the lower side wall 62b of the intermediate member 60 is compressed and deformed by the pressing force caused by the rotation of the head 54. As a result, the lower side wall portion 62b absorbs the pressing force of the head portion 54, and the load applied to the bottom side 57a of the frame portion 57 is alleviated.

Subsequently, assembly of the brush holder unit 70 to the front case 3 will be described.
Before assembling the brush holder unit 70 to the front case 3, the brush 72 and the spring 78 are accommodated in the first holder body 81 and the second holder body 82 of the brush holder 71 in advance, respectively. At this time, one end of the pigtail 77 is connected to the brush 72 by brazing, for example. Further, a terminal 89 is attached to the other end of the pigtail 77 of the brush 72 housed in the first holder main body 81. The other end of the pigtail 77 of the brush 72 housed in the second holder body 82 may be connected in advance to the pigtail connection portion 63 of the intermediate member 60, or the brush holder unit 70 may be assembled to the front case 3 After that, it may be connected to the pigtail connection 63.

Then, after the brushes 72 and the springs 78 are stored in the first holder body 81 and the second holder body 82, respectively, the base portion 90 is assembled to the brush holder 71, and the assembly of the brush holder unit 70 is completed.
Thereafter, with the base portion 90 directed to the bottom portion 3a of the front case 3, the side rib 30a on the side of the recess 28 of the front case 3, ie, the side on which the bolt seat 31 is formed, the first contact convex portion 30c1, and The brush holder unit 70 is placed on the intermediate rib 30 d.

At this time, the brush holder unit 70 is mounted so that the inlay convex portion 32 formed on the bolt seat 31 of the front case 3 is fitted in the through hole 88 a of the pedestal 88 of the brush holder 71. Further, the brush holder unit 70 is placed such that the first contact convex portion 30c1 is inserted between the positioning convex portion 84 and the position regulating convex portion 85 of the brush holder 71. Thereby, the position of the brush holder unit 70 with respect to the front case 3 is temporarily determined.
Here, when mounting the brush holder unit 70 on the bottom portion 3 a of the front case 3, the base portion 90 is directed to the bottom portion 3 a of the front case 3. 1 Positioning convex part 84 and the 3rd convex part 85 enter into a worker's blind spot.

  The circumferential center L6 of the positioning projection 83 formed on the upper wall 75 of the first holder main body 81 extends along the axial direction and passes through the circumferential center of the first holder main body 81 (second opening 81b). It is located on the straight line L5 (see FIG. 10). Further, the positioning convex portion 84 formed at the edge of the first opening 81a of the first holder main body 81 is formed such that one side 84a faces the straight line L5. Therefore, when the operator visually recognizes the position of the positioning projection 83, it is possible to recognize the approximate position of the positioning convex portion 84 or the third convex portion 85 which is a dead angle. Therefore, it is easy for the operator to place the brush holder unit 70 so that the first contact convex portion 30c1 is inserted between the positioning convex portion 84 and the position restricting convex portion 85 of the brush holder 71. Can be done.

  After temporary determination of the position of the brush holder unit 70 with respect to the front case 3, the bolt 101 is screwed onto the female screw 33 of the inlay convex portion 32 of the front case 3 from above the pedestal 88 of the brush holder 71. At this time, the terminals 89 attached to the pigtails 77 of the brushes 72 stored in the first holder main body 81 are also tightened together.

FIG. 12 is a plan view of the mounting state of the brush holder unit 70 on the front case 3 as viewed from the motor case 2 side.
As shown in the figure, as the bolt 101 is tightened (see arrow Y3 in FIG. 12), the brush holder unit 70 tries to rotate together with the bolt 101. That is, the brush holder unit 70 tries to rotate around the bolt 101 in the tightening direction of the bolt 101 (see arrow Y4 in FIG. 12).

  Then, one side 84 a of the positioning convex portion 84 of the brush holder 71 abuts on the first abutting side surface 30 e on the side rib 30 a side of the first abutting convex portion 30 c 1 in the front case 3. When the bolt 101 is further tightened, the brush holder unit 70 is attached to the front case 3 with one side 84 a of the positioning convex portion 84 kept in contact with the first abutting side surface 30 e of the first abutting convex portion 30 c 1. Are fastened and fixed. Thereby, positioning of the brush holder unit 70 with respect to the front case 3 is performed. That is, among the plurality of ribs 30 formed in the concave portion 28 of the front case 3, the first contact convex portion 30 c 1 has a role of improving the strength of the front case 3 and a brush for the front case 3 It has a role of positioning the holder unit 70.

  Here, the first abutting side surface 30e of the first abutting convex portion 30c1 of the front case 3 faces the radial straight line L4 passing through the rotation axis L1 and the axial direction. Further, the positioning convex portion 84 of the brush holder 71 is formed such that one side 84a faces a straight line L5 extending in the axial direction and passing through the circumferential center of the brush 72 (second opening 81b). Therefore, when the brush holder unit 70 is fastened and fixed to the front case 3 with the one side 84a of the positioning convex portion 84 in contact with the first abutting side surface 30e of the first abutting convex portion 30c1, The circumferential center of the brush 72 accommodated in the holder body 81 coincides with the radial straight line L4 passing through the rotation axis L1. That is, the direction of the brush 72 is in the radial direction, and the brush 72 is positioned with high accuracy.

  Further, when the bolt 101 is tightened while the one side 84 a of the positioning convex portion 84 of the brush holder 71 is in contact with the first abutting side surface 30 e on the side rib 30 a side of the first abutting convex portion 30 c 1, The pressing force of the positioning projection 84 acts on the first contact projection 30c1. Then, the pressing force acts as a reaction force, and a force acts on the brush holder 71.

  Here, in the brush holder 71, the inner peripheral wall portion 87 of the connecting portion 74 connecting the two holder main bodies 81 and 82 is formed to straddle between the radially inner ends of the two holder main bodies 81 and 82. . For this reason, since the circumferential length of the inner circumferential wall 87 can be set as short as possible, the strength of the inner circumferential wall 87 is secured, and the deformation of the inner circumferential wall 87 due to the force acting on the brush holder 71 is prevented. Ru.

  That is, for example, when the inner peripheral wall 87 is formed so as to straddle between the radial outer ends of the two holder main bodies 81 and 82, the inner peripheral wall 87 is the radial inner end of the two holder main bodies 81 and 82. The circumference becomes longer compared to the case of straddling the interval. As the inner peripheral wall portion 87 becomes longer, the strength is reduced by this amount, and it becomes easily influenced by the force acting on the brush holder 71. Therefore, by setting the circumferential length of the inner circumferential wall portion 87 as short as possible, the strength of the inner circumferential wall portion 87 can be increased.

On the other hand, when the bolt 101 is loosened in order to remove the brush holder unit 70 from the front case 3, the brush holder unit 70 tries to rotate together. That is, the brush holder unit 70 tries to rotate around the bolt 101 in the loosening direction of the bolt 101 (see the arrow Y5 in FIG. 12).
Then, the position restricting convex portion 85 of the brush holder 71 abuts on the second abutting side surface 30 f (see FIG. 5) opposite to the side rib 30 a of the first abutting convex portion 30 c 1 in the front case 3. Therefore, when the bolt 101 is loosened in order to remove the brush holder unit 70 from the front case 3, the brush holder unit 70 is prevented from swinging around.

(Assembly of motor case and front case)
Next, assembly of the motor case 2 and the front case 3 will be described.
Here, as described above, the terminal 64 and the brush holder unit 70 are assembled to the motor case 2 in advance. On the other hand, the sliding bearing 12 is attached to the bearing 9 in advance and the armature 4 is attached to the motor case 2 in advance.
In this state, the inlay portion 2c of the motor case 2 and the inlay portion 3d of the front case 3 are opposed to each other. Further, the positions of the notch 2 b formed in the inlay portion 2 c of the motor case 2 and the positioning projection 83 of the brush holder unit 70 attached to the front case 3 are aligned.

  Then, when the motor case 2 and the front case 3 are superimposed, the inlay portion 3 d of the front case 3 is inlay fitted with the inlay portion 2 c of the motor case 2. At the same time, the positioning projection 83 of the brush holder unit 70 attached to the front case 3 is fitted into the notch 2 b formed in the inlay portion 2 c of the motor case 2. Thereby, circumferential positioning of the front case 3 with respect to the motor case 2 is performed. That is, the brush holder unit 70 (brush holder 71) is positioned with reference to the motor case 2.

  Here, the motor case 2 is provided with a plurality of (for example, four in the present embodiment) magnets 8, and these magnets 8 are also positioned based on the motor case 2. For this reason, positioning of the brush holder unit 70 (brush holder 71) with respect to the magnet 8 is performed with high precision. As a result, positioning of the brush 72 with respect to the magnet 8 is performed with high accuracy (see FIG. 12).

(Operation of starter motor)
Next, the operation of the starter motor 1 will be described.
The terminal bolt 52 is electrically connected to the pigtail 77 via the intermediate member 60. Therefore, when a voltage is applied to the terminal bolt 52, a current is supplied to the segment 21 of the commutator 16 with which the brush 72 is in sliding contact. Here, since the position of the brush 72 is positioned with high precision along the radial direction, the brush 72 is in good sliding contact with the segment 21.

The current supplied to the segment 21 is further supplied to the coil 19. Then, a predetermined magnetic field is formed on the teeth 18 of the armature core 15, and a magnetic attractive force or repulsive force is generated between the magnetic field and the magnet 8 provided on the motor case 2. Thereby, the armature 4 rotates.
Here, since the position of the brush 72 is positioned with high accuracy with respect to the magnet 8, the relationship between the position of the magnetic field formed in the armature core 15 and the position of the magnet 8 becomes good. For this reason, the armature 4 is rotated efficiently.
The rotation of the armature 4 is transmitted to the ring gear of the engine through the pinion gear 17 and a one-way clutch (not shown). This starts the engine.

  As described above, in the above-described embodiment, the brush holder 71 is fastened and fixed to the front case 3 by the bolt 101 using the pedestal 88 formed in the connecting portion 74. Further, a positioning convex portion 84 is formed to be protruded from the brush holder 71, and when the bolt 101 is tightened, the positioning convex portion 84 is formed on the first abutting side surface 30 e of the first abutting convex portion 30 c 1 of the front case 3. One side 84 a comes in contact with the other. That is, when the brush holder 71 is fastened and fixed to the front case 3, the positioning convex portion 84 of the brush holder 71 is always in contact with the first contact convex portion 30 c 1. Therefore, the position of the brush holder 71 with respect to the front case 3 can be stably determined with high precision, and the performance of the starter motor 1 can be stably improved.

  Further, on the brush holder 71, a position regulation convex portion 85 is formed to protrude on the opposite side to the positioning convex portion 84 with the first contact convex portion 30c1 interposed therebetween. Therefore, when loosening the bolt 101 in order to remove the brush holder unit 70 from the front case 3, the position control convex portion 85 abuts on the first contact convex portion 30 c 1, and the swinging of the brush holder unit 70 can be prevented. Therefore, when assembling the brush holder unit 70 (brush holder 71), rattling at the time of removal can be suppressed as much as possible.

  Furthermore, one of the first contact convex portions 30c1 has a plurality of functions such as reinforcement of the front case 3, positioning of the brush holder unit 70, and prevention of swinging when the brush holder unit 70 is removed. . For this reason, the part arrange | positioned to front case 3 can be reduced. Therefore, the material cost of the front case 3 can be reduced, and the front case 3 and the brush holder unit 70 (brush holder 71) can be miniaturized.

  Further, the first contact side surface 30e of the first contact convex portion 30c1 of the front case 3 faces the radial straight line L4 passing through the rotation axis L1 and the axial direction. Further, the positioning convex portion 84 of the brush holder 71 is formed such that one side 84a faces a straight line L5 extending in the axial direction and passing through the circumferential center of the brush 72 (second opening 81b). Therefore, when the brush holder unit 70 is fastened and fixed to the front case 3 with the one side 84a of the positioning convex portion 84 in contact with the first abutting side surface 30e of the first abutting convex portion 30c1, The circumferential center of the brush 72 accommodated in the holder body 81 coincides with the radial straight line L4 passing through the rotation axis L1. That is, the direction of the brush 72 is along the radial direction, and the positioning of the brush 72 can be performed with high accuracy. As a result, the contact state of the brush 72 with the segment 21 of the commutator 16 is improved, and the life of the brush 72 can be extended.

  Furthermore, while the positioning protrusion 83 is formed to be protruded from the brush holder 71, the notch 2 b is formed in the inlay portion 2 c of the motor case 2. Then, when assembling the motor case 2 and the front case 3, the tongue piece 83 b of the positioning projection 83 is fitted in the notch 2 b of the motor case 2, whereby the motor case 2 and the front case 3 are circumferentially Not only positioning is performed, but also circumferential positioning of the motor case 2 and the brush holder 71 (brush holder unit 70) is performed.

Therefore, the position of the brush holder 71 with respect to the motor case 2 can be determined with high accuracy. That is, positioning of the brush holder 71 and positioning of the magnet 8 can be performed with reference to the motor case 2. Therefore, the relative position between the brush 72 held by the brush holder 71 and the magnet 8 can be easily determined with high accuracy, and the performance of the starter motor 1 can be improved.
Further, when the brush holder 71 and the motor case 2 are engaged with each other in a concavo-convex manner, the brush holder 71 is made convex (positioning projection 83). Therefore, the convex shape can be easily formed as compared with the case where the convex shape is formed on the motor case 2 side. The manufacturing cost of the starter motor 1 can be reduced by this amount.

  Furthermore, the brush holder 71 includes two holder main bodies 81 and 82 (first holder main body 81 and second holder main body 82) for holding the brush 72, and two holder main bodies 81, straddling these two holder main bodies 81 and 82, A connecting portion 74 for connecting 82 is integrally formed. The connection portion 74 extends in an arc shape along the outer peripheral surface of the bearing portion 22 (commutator 16). In other words, the connecting portion 74 extends in an arc along the inner peripheral surface of the peripheral wall 3 b of the front case 3. Thus, the connecting portion 74 can be disposed in the minimum space without creating a dead space. Therefore, while the two brushes 72 are integrated by the brush holder 71, the space occupied by the brush holder 71 can be minimized to improve the layout of each component. As a result, the starter motor 1 can also be miniaturized.

Further, in the brush holder 71, the inner circumferential wall portion 87 of the connecting portion 74 connecting the two holder main bodies 81 and 82 is formed to straddle between the radially inner ends of the two holder main bodies 81 and 82. Therefore, the circumferential length of the inner circumferential wall portion 87 can be set as short as possible. For this reason, the material cost of the brush holder 71 can be reduced.
Furthermore, the strength of the inner circumferential wall portion 87 is secured, and the force applied to the brush holder 71 can prevent the inner circumferential wall portion 87 from being deformed. That is, for example, when the inner peripheral wall 87 is formed so as to straddle between the radial outer ends of the two holder main bodies 81 and 82, the inner peripheral wall 87 is the radial inner end of the two holder main bodies 81 and 82. The circumference becomes longer compared to the case of straddling the interval. As the inner peripheral wall portion 87 becomes longer, the strength is reduced by this amount, and it becomes easily influenced by the force acting on the brush holder 71. Therefore, by setting the circumferential length of the inner circumferential wall portion 87 as short as possible, the strength of the inner circumferential wall portion 87 can be increased.

In order to position the motor case 2 and the brush holder 71 (the brush holder unit 70) in the circumferential direction, the first positioning projection 83 fitted in the notch 2b of the motor case 2 is located on the first holder body 81. It is formed at the radially outer end of the wall 75.
Here, the distance between the radially outer end of the first holder main body 81 and the peripheral wall 3 b of the front case 3 is shorter than the distance between the connecting portion 74 and the peripheral wall 3 b of the front case 3. Therefore, by providing the positioning protrusion 83 at the radial outer end of the first holder main body 81, the radial extension length of the positioning protrusion 83 (compared to the case where the first positioning protrusion 83 is provided in the connecting portion 74) The extension length of the tongue 83 b can be set short. Therefore, the material cost of the brush holder 71 can be reduced.

  Furthermore, the circumferential center L6 of the positioning protrusion 83 formed on the upper wall 75 of the first holder main body 81 is along the axial direction and passes through the circumferential center of the first holder main body 81 (second opening 81 b) It is located on the straight line L5 (see FIG. 10). Further, the positioning convex portion 84 formed at the edge of the first opening 81a of the first holder main body 81 is formed such that one side 84a faces the straight line L5. For this reason, when the operator visually recognizes the position of the positioning projection 83, it is possible to recognize the approximate position of the positioning convex portion 84 or the position regulating convex portion 85 which is a blind spot. Therefore, it is easy for the operator to place the brush holder unit 70 so that the first contact convex portion 30c1 is inserted between the positioning convex portion 84 and the position restricting convex portion 85 of the brush holder 71. Can be done.

  The terminal 64 also has a terminal insulator 55 for holding the substantially square head 54 of the terminal bolt 52 at a position corresponding to the terminal seat 50 formed on the peripheral wall 3 b of the front case 3, and the terminal insulator 55. And an intermediate member 60 interposed between the head 54 and the head 54. Furthermore, after the base 57 a of the substantially square frame 57 is brought into contact with the recess 28 of the front case 3, the lower side wall 62 b of the intermediate member 60 is interposed between the base 57 a and the head 54. I am disguised.

  Therefore, when the nut 59 is tightened on the shaft portion 53 of the terminal bolt 52, the front case 3 receives the load that the terminal bolt 52 (head 54) tries to rotate together via the bottom side 57a of the frame portion 57. The rotation of the bolt 52 with the nut 59 can be prevented. At this time, the load by the head 54 of the terminal bolt 52 is positively applied to the bottom side 57 a of the frame portion 57. However, the load can be absorbed by the intermediate member 60 which is harder than the terminal insulator 55 and softer than the terminal bolt 52. Thus, the terminal insulator 55 can be prevented from being deformed or damaged, and the insulation between the front case 3 and the terminal bolt 52 (head 54) can be reliably ensured.

  Further, the head portion 54 of the terminal bolt 52 housed in the terminal insulator 55 satisfies the conditions (A), the conditions (B) and the conditions (C). That is, in the frame portion 57, the head 54 is in contact with only the bottom side 57a. For this reason, when the head portion 54 is to rotate, the pressing force of the head portion 54 can be positively applied to the bottom side 57 a of the frame portion 57. On the other hand, the pressing force of the head 54 can be substantially prevented from being applied to the other side (upper side 57 b and side 57 c) of the frame portion 57.

  In other words, the load by the head 54 can be reliably applied to the bottom side 57 a of the frame portion 57 in contact with the recess 28 of the front case 3, and this load can be reliably received by the front case 3. As a result, with the front case 3, deformation of the bottom side 57 a of the frame portion 57 can be reliably suppressed, and damage to the terminal insulator 55 can be prevented. In addition, the rotation of the head portion 54 can be reliably prevented, and the nut 59 can be firmly tightened to the shaft portion 53 of the terminal bolt 52.

Instead of receiving the load applied to the terminal insulator 55 by the recess 28 of the front case 3, it is also possible to separately provide a receiving plate on the front case 3 and receive the load applied to the terminal insulator 55 by this receiving plate. In this case, the receiving plate is positively brought into contact with the frame portion 57 of the terminal insulator 55.
However, by bringing the bottom side 57 a of the terminal insulator 55 into contact with the recess 28 of the front case 3 as in the above-described embodiment, it is not necessary to separately provide a receiving plate on the front case 3. Therefore, the number of parts of the starter motor 1 can be reduced, or the material cost of the front case 3 can be reduced. Moreover, since it is not necessary to provide a receiving plate separately, the front case 3 can be miniaturized.

  Further, a pigtail connecting portion 63 for connecting the pigtail 77 is bent and extended in the axial direction on the upper side wall portion 62a of the two side wall portions 62a and 62b of the intermediate member 60. Therefore, it is not necessary to connect the pigtail 77 directly to the head 54 of the terminal bolt 52. That is, the pigtail 77 and the head 54 of the terminal bolt 52 can be electrically connected through the pigtail connection portion 63 and the intermediate member 60. As a result, the degree of freedom in the layout of the pigtails 77 can be increased. For example, the distance between the brush 72 and the pigtail connection portion 63 can be set as short as possible, and the length of the pigtail 77 can also be set short. In such a case, the wire cost of the pigtail 77 can be reduced.

  The pigtail connection portion 63 (intermediate member 60) is made of a brass plate material. Furthermore, the pigtail 77 is also made of copper wire. That is, the specific heat of the pigtail connection portion 63 and the specific heat of the pigtail 77 can be set substantially equal. Therefore, when the pigtail 77 is connected to the pigtail connection portion 63 by, for example, brazing welding, the welding operation can be easily performed.

The present invention is not limited to the above-described embodiment, and includes the above-described embodiment with various modifications, without departing from the spirit of the present invention.
For example, the case where a structure like the above-mentioned embodiment was adopted as starter motor 1 for two wheels was explained. However, the present invention is not limited to this, and the configurations as described above can be adopted for motors and generators of various specifications.

  The motor case 2 has been described, for example, in the case where the iron plate is formed by deep drawing. Moreover, the front case 3 demonstrated the case where it formed by aluminum die-cast, for example. Furthermore, the case where the bracket 5 is formed of a metal plate such as iron has been described. However, the present invention is not limited to these, and the materials of the motor case 2, the front case 3 and the bracket 5 can be variously selected.

  Furthermore, in the above-described embodiment, while the positioning protrusion 83 is formed in the brush holder 71 in a projecting manner, the notch 2b is formed in the motor case 2 and the positioning protrusion 83 is fitted into the notch 2b. However, the present invention is not limited to this. While providing a protrusion on the motor case 2, a recess may be formed on the brush holder 71, and the protrusion of the motor case 2 may be fitted into this recess.

Further, in the above-described embodiment, the brush holder 71 includes two holder bodies 81 and 82 (a first holder body 81 and a second holder body 82), and two holder bodies 81 straddling the two holder bodies 81 and 82. , 82 are integrally formed. However, the present invention is not limited to this, and two or more holder main bodies 81 and 82 for holding the brush 72 may be provided according to the motor specification.
Furthermore, in the above-described embodiment, the case where the connection portion 74 of the brush holder 71 extends in an arc shape along the inner peripheral surface of the peripheral wall 3b of the front case 3 has been described. However, the present invention is not limited to this, and various shapes can be adopted according to the layout of the brush holder 71, the arrangement of other components, and the like.

Further, in the above-described embodiment, reinforcement of the front case 3, positioning of the brush holder unit 70, and prevention of runaway at the time of removal of the brush holder unit 70 are performed by one of the first contact convex portions 30 c 1 of the front case 3. The case where it has a plurality of functions, has been described. However, the present invention is not limited to this, and a convex portion in contact with one side 84 a of the positioning convex portion 84 when the bolt 101 is tightened to the front case 3 and a convex in contact with the position control convex portion 85 when the bolt 101 is loosened. The units and may be provided separately. Also, only one function of these convex portions may be provided to the first contact convex portion 30c1.
In addition, when providing the convex part contact | abutted with the one side 84a of the positioning convex part 84 when fastening the volt | bolt 101 to the front case 3 separately from 1st contact convex part 30c1, it is desirable to comprise as follows. That is, it is desirable that the contact surface of the projection with the side 84 a of the positioning projection 84 faces the radial straight line L 4 passing through the rotation axis L 1 and the axial direction.

  Moreover, in the above-mentioned embodiment, the case where the intermediate member 60 of the terminal 64 was formed by pressing a brass plate was described. However, the present invention is not limited to this, and the intermediate member 60 may be made of a conductive material. As a result, the intermediate member 60 deforms under the load of the head portion 54 of the terminal bolt 52, and the intermediate member 60 can absorb the load of the head portion 54.

  Furthermore, in the above-described embodiment, the intermediate member 60 includes the base portion 61 and the two side wall portions 62 a bent and extended along the inner side surface of the frame portion 57 from both ends (axial direction ends) of the base portion 61. , 62b (upper side wall portion 62a, lower side wall portion 62b), the case where it is formed in a substantially U-shaped cross section has been described. However, the intermediate member 60 is not limited to this, and at least between the bottom side 57a of the frame portion 57, that is, the bottom side 57a in contact with the recess 28 of the front case 3 and the head 54 of the terminal bolt 52. It should just be interposed. In the intermediate member 60, side walls 62a and 62b may be formed all around the outer peripheral edge of the base 61.

  Moreover, in the above-mentioned embodiment, the case where the frame portion 57 of the terminal insulator 55 is in contact with the recess 28 of the front case 3 has been described. The case where the load applied to the terminal insulator 55 is received by the recess 28 of the front case 3 has been described. However, the present invention is not limited to this, and a front plate 3 may be separately provided with a receiving plate for receiving a load applied to the terminal insulator 55. In this case, the receiving plate is positively brought into contact with the frame portion 57 of the terminal insulator 55.

Furthermore, in the above-mentioned embodiment, the case where the head portion 54 of the terminal bolt 52 and the frame portion 57 of the terminal insulator 55 for holding the head portion 54 are respectively formed in a substantially square shape has been described. However, the present invention is not limited to this, and the head portion 54 and the frame portion 57 may be formed in a polygonal shape. For example, it may be formed in a rectangular shape long in the circumferential direction.
Moreover, in the above-mentioned embodiment, the case where the pigtail connection portion 63 is bent and extended in the axial direction on the upper side wall portion 62a of the two side wall portions 62a and 62b of the intermediate member 60 has been described. However, as long as the pigtail connection portion 63 is formed in the intermediate member 60, the shape and the formation location thereof are not particularly limited.

  Furthermore, in the above-described embodiment, the connecting portion 74 of the brush holder 71 includes the base portion 86 straddling between the end portions on the front case 3 side of the two holder main bodies 81 and 82 and the two holder main bodies 81 and 82. The case of being constituted by the inner peripheral wall portion 87 straddling between the radially inner ends is described. However, the present invention is not limited to this, and the connecting portion 74 may have at least the inner circumferential wall portion 87. In this case, the pedestal 88 may be formed to protrude from the connecting portion 74.

1 ... Starter motor (rotary electric machine)
2 Motor Case 2a Opening 3 Front Case (End Case)
4 Armature 6 Yoke portion 8 Magnet 16 Commutator 30 Rib 30c1 First contact convex portion (first positioning convex portion, third convex portion)
30e ... first contact side surface (contact surface)
70 ... brush holder unit 71 ... brush holder 72 ... brush 84 ... positioning convex part (second positioning convex part)
84a ... one side (contact surface)
85 ... Position regulation convex part (fourth convex part)
101 ... bolt L1 ... rotation axis L4 ... straight line (straight line in radial direction)
L5 ... straight line

Claims (4)

A motor case having a cylindrical yoke portion and a magnet provided on the yoke portion;
An end case provided to close the opening of the motor case and having a first positioning protrusion;
An armature rotatably supported by the motor case and the end case and having a commutator;
A plurality of brushes in sliding contact with the commutator;
A brush holder for holding the plurality of brushes in a movable manner toward the commutator and having a second positioning protrusion;
Equipped with
The brush holder is fastened and fixed to the end case by one bolt,
The rotary electric machine according to claim 1, wherein the second positioning convex portion is disposed to abut on the first positioning convex portion in a tightening direction of the bolt. The end case has a third convex portion, while the brush holder has a fourth convex portion.
The rotating electrical machine according to claim 1, wherein the fourth convex portion is disposed to abut on the third convex portion in a loosening direction of the bolt. The rotary electric machine according to claim 2, wherein the first positioning convex portion also has a function of the third convex portion. The first positioning convex portion is a rib provided on the end case, and the contact surface of the rib with the second positioning convex portion is a radial straight line passing through the rotation axis of the armature and an axial direction It is formed to face the
The contact surface of the second positioning convex portion with the first positioning convex portion is formed to face a straight line passing along the axial direction and passing through the circumferential center of the brush to be held. The rotary electric machine according to any one of claims 1 to 3.

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